Ceramide induces translocation of protein kinase C-α to the Golgi compartment of human embryonic kidney cells by interacting with the C2 domain
Ceramide induces translocation of protein kinase C-α to the Golgi compartment of human embryonic kidney cells by interacting with the C2 domain
复制标题
DOI：
10.1016/j.bbalip.2003.08.004
复制
发表时间：
2003-10-20
影响因子：
4.8
通讯作者：
Huwiler, A
中科院分区：
文献类型：
--
作者：
Aschrafi, A;Franzen, R;Huwiler, A
神经酰胺是一种脂质第二信使，在暴露于有限数量的激动剂的细胞中由鞘脂代谢产生，进而引发包括蛋白激酶C (PKC)- α激活在内的重要细胞反应。利用含有牛PKCalpha和绿色荧光蛋白（GFP）的融合蛋白，我们转染了人胚胎肾（HEK）细胞，并研究了亚细胞间室神经酰胺触发PKCa重分布的原因。外源性c16神经酰胺或细菌鞘磷脂酶（bSMase）刺激HEK细胞，导致内源性神经酰胺形成增加，引起PKCalpha向高尔基筋膜室易位。通过使用在调控区域缺乏不同结构域的PKC(x)的缺失突变体，研究表明Ca2+依赖性脂质结合C2结构域，而不是一个c1结构域，是神经酰胺触发的PKCalpha向高尔基复合体易位所必需的。相比之下，C2结构域不需要磷酸酯（TPA）结合和PKCalpha向质膜的易位。此外，有证据表明TPA只需要两个C1亚结构域中的一个就可以触发向质膜的易位。总之，我们的数据提供了证据，神经酰胺直接或间接地与Ca2+依赖性脂质结合PKCalpha的C2结构域相互作用，从而诱导酶易位到高尔基室。(C) 2003 Elsevier B.V.版权所有
Ceramide is a lipid second messenger produced by sphingolipid metabolism in cells exposed to a limited number of agonists and in turn triggers important cell responses including protein kinase C (PKC)-alpha activation. Using a fusion protein comprising bovine PKCalpha and the green fluorescent protein (GFP),. we transfected human embryonic kidney (HEK) cells and investigated to which subcellular compartment ceramide triggers PKCa redistribution. Stimulation of HEK cells with exogenous C16-ceramide or bacterial sphingomyelinase (bSMase), which leads to increased endogenous ceramide formation, evokes a translocation of PKCalpha to the Golgi compartment. By using deletion mutants of PKC(x lacking distinct domains in the regulatory region, it is shown that the Ca2+-dependent lipid binding C2 domain, but not one of the C I domains is essentially required for the ceramide-triggered translocation of PKCalpha to the Golgi complex. In contrast, the C2 domain is not required for phorbol ester (TPA) binding and translocation of PKCalpha to the plasma membrane. In addition, evidence is provided that TPA requires only one of the two C1 subdomains to trigger translocation to the plasma membrane.In summary, our data provide evidence that ceramide either directly or indirectly interacts with the Ca2+-dependent lipid binding C2 domain of PKCalpha and thereby induces translocation of the enzyme to the Golgi compartment. (C) 2003 Elsevier B.V. All rights reserved.